Conventional systems exist that perform gesture recognition, i.e. interpreting user motion as input to a system. For example, touch screen based systems collect user inputs using a touch screen that monitors changes in capacitance and/or resistance on the touch screen to identify the position of user input from a stylus or finger in contact with the touch screen. Changes in the capacitance and/or resistance are interpreted to determine the user's motion. By way of another example, some optical systems capture optical input on a pixel array basis and identify motion by analyzing changes in the pixel data.